Monthly Archives: April 2018

This tip will help you troubleshooting DNS issues by directly querying DNS using only the IP address of name servers. When you run dns resolution client tools such as dig or nslookup, they will query the name server configured on your host. If the DNS with unexpired ttl is in cache, they will return it from cache. The results will return from cache by any of the intermediate name servers except for the authoritative name servers. That is why ‘dig +trace’ is useful in troubleshooting dns issues, as it starts from the root name servers and moves down all the way to the authoritative name servers to get you the dns records.

Here is a similar tool to “dig +trace”, which queries root name servers, their IPs is hard coded in the script, and follows the authoritative name servers for the subdomains by directly querying the registered IP addresses of name servers. For instance, if you use this tool to query “www.example.com”, it will get a randomly picked root name server’s IP and query it for NS records of “.com” domain. Once it gets the IP address of the name servers for “.com”, it goes on to query them for authoritative name servers of “example.com.” and does the same for “www.example.com.” as well. Throughout the query, it doesn’t use any cache or FQDN, it get the IP address of authoritative name servers and queries the IP directly.

1. Clone your github repo to your local file system.
2. change to the cloned directory
3. Add below shell script to your repo directory and run it –
Make sure to update the first three variables OLD_EMAIL, CORRECT_NAME, and CORRECT_EMAIL to appropriate values.

cat conCATenates one or more files given as argument and prints those on the standard output (console).
If no file or ‘-‘ (dash) is given, it reads from standard input until EOF (Ctrl+D) is pressed and prints is to standard output.

$ ls -l linus # ls to make sure file exists
-rw-rw-r-- 1 daniel daniel 403 Apr 15 01:20 linus
$ cat linus # print content of file to stdout
Hello everybody out there using minix -
I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones.
This has been brewing since april, and is starting to get ready.
I'd like any feedback on things people like/dislike in minix,
as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).
$ cat -n linus # show line numbers with -n
1 Hello everybody out there using minix -
2
3 I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones.
4 This has been brewing since april, and is starting to get ready.
5 I'd like any feedback on things people like/dislike in minix,
6 as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).
$ cat # read from stdin(keyboard) and print to stdout(screen), repeats after me until I press Ctr+D to end it.
reading
reading
from standard inpu
from standard inpu
pressing Ctr+D now
pressing Ctr+D now
$ cat << EOF > file-from-stdin # Reads from keyboard until EOF is pressed and saves(redirects) the text to a file.
I read this from stdin
end of file
EOF
$ ls -l file-from-stdin # printing content of file we created above.
-rw-rw-r-- 1 daniel daniel 35 Apr 15 01:22 file-from-stdin
$ cat file-from-stdin
I read this from stdin
end of file

4. clear – clears the terminal screen.

clear is self-explanatory, it clears the terminal display and places your cursor at the top left corner. Similar to “cls” command in DOS/Windows/PowerShell.

Use rmdir to delete the named directory, not its contents. To completely wipe out a directory and its contents use ‘rm -r’.

6. mkdir – make or create one or more directories.

mkdir is used to create one or more directories under current directory if no directory argument is given. The user creating the directory must have the permission to create a directory under the specified directory.

Getting your first online freelancing assignment is not that easy. In general, there is lots of competition but most of all the established professional on the particular online platform will take most of the bids. That makes it really difficult for new sign ups to win any of the bids as they haven’t built any reputation within that platform. Online freelancing platforms such as Upwork, allow the freelancers or contractors to create a profile – more like an online resume – plus all the feedback and ratings they have received from the employers on the particular platform. So when a new assigned is posted, the employers will in nearly all cases look for someone who has been rated well and that doesn’t give new comers any chance.

Here are some of the tips you can use to improve your chances of getting your first bid, as that is really crucial whether you will make it in a particular freelancing platform or not. If you have a presence in several freelancing sites, your ratings and feedback don’t get transferred to other sites, which means you have to start from scratch to prove your worth.

Let us get to the tips –

1. Be patient, be patient, be patient – it takes time, landing your first assignment is tough but once you get it and your employers leaves you a good feedback with a high rating, upcoming bids become a lot easier. This could take weeks or even months for some folks.

2. Do not overcharge – In fact, I would say set your rate way below the average for your particular area of work. Look at the other bidders, and make sure you get noticed for your much lower fees. Remember, at this point your highest priority is not money, it is the feedback and rating. You will have plenty of time to hike your fees later 🙂

3. Read the job description carefully – Since most of the bids get lots of bidders, the way the employers try to narrow down the candidates is by picking the ones who follow the instructions. The employer will put some information in the job description, such as respond with “the text XYZ” at the top of your response email. Anyone who doesn’t follow the instruction will not get a chance. Besides, reading the job description carefully will help you figure out whether this task is the right one for you or not.

4. Bid to an assignment that you know you will accomplish it really well – remember this is your first task, pick it carefully. You have to be confident that you can accomplish this task really well and get a good feedback. You will pick and choose later, don’t be picky now.

5. Create a stellar profile – as a newbie freelancer for this particular freelancing site, most potential employers won’t look at your profile, they filter out candidates based on how long they have been on the site, how many ratings they have, total number of assignments they worked on etc. But if for some reason an employer decides to give you a chance, you better make sure they find all the information they need in your profile.

6. Respond fast to emails/text from potential employers – show them that you won’t vanish when an urgent assignment comes in! Most of the employers have to report to someone too, and they will ask for your progress status etc. Make sure that they can reach out to you in a predictable manner. Let them know your working hours, and how long it might take you to respond and the communication channel that they can reach you, whether it is through messaging service provided by the freelancing site, skype, gmail etc.

7. Don’t burn bridges – it is a small world, make sure you leave on good terms.

8. Research the employers – There are good and bad employers in the online freelancing world, make sure to research the employers as well. Look at their profile in the platform, check how other candidates rated them. Especially pay attention to how many jobs they posted and how many hires they actually made, this ratio is very important.

9. Don’t sound needy or desperate – I know you really want to get your first assignment, and I am sure you will get it with enough perseverance. But don’t be too needy in your communication with potential employers. Be confident and use language which shows that you are familiar with the task and that you will deliver.

10. Watch out for impostors – some will try to get answers without signing a contract, some might try to blackmail you knowing that this is your first assignment and how desperate you are to get a good feedback and rating from them. So make sure to research the employers as well.

I hope this list of tips helps, Good luck with winning your first bid!

When you run a Linux command and pipe it through grep, the grep text itself is shown in the output as well. Once common technique is to use “grep -v” to exclude it. But here is a handy tip which excludes the grep text by placing the first character in a parenthesis –

In Linux, it is very common to expect the files in the system to follow certain naming conventions – such as no white space, usually only lower cases, alphanumeric with underscore or dashes. But in some cases, you will find files which don’t follow this convention – the files might have been copied from other OSes such as Microsoft Windows or MacOS. Here is a trick to empty these files without deleting them.

Use the “truncate” command to empty files with non-standard names.

Requirement – empty files with white space in file name. Keep the files, just reduce the size to 0.